Removal of cadmium and zinc from contaminated wastewater using Rhodobacter sphaeroides

2016 ◽  
Vol 75 (11) ◽  
pp. 2489-2498 ◽  
Author(s):  
Xiaomin Li ◽  
Weihua Peng ◽  
Yingying Jia ◽  
Lin Lu ◽  
Wenhong Fan
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Removal Rate ◽  
Inoculum Size ◽  
Pilot Test ◽  
Optimal Conditions ◽  
Practical Application ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Effects Of Ph ◽  
Remediation Time

Rhodobacter sphaeroides was used for bioremediation of wastewater polluted with cadmium (Cd) and zinc (Zn). The tolerance of the microorganism to selected heavy metals (HMs), as well as the effects of pH, temperature and inoculum size on the removal rate, was investigated. The remediation effects of R. sphaeroides were analysed at different initial concentrations of HMs. Bioremediation mechanisms were thoroughly discussed based on the results from the cell characterisation analysis. Cd and Zn could inhibit the growth of R. sphaeroides. However, Cd was more toxic than Zn, with corresponding EC50 values of 5.34 and 69.79 mg L−1. Temperature and pH had greater influence on the removal rate of HMs than inoculum size. The optimal conditions for temperature and pH were 35 °C–40 °C and pH 7, respectively. Initial concentration of HMs and remediation time also affected the removal rate. Rhodobacter sphaeroides had a relatively higher remediation effect under the present experimental conditions. The removal rates for Cd and Zn reached 97.92% and 97.76%, respectively. Results showed that biosorption and HM precipitation were the main bioremediation mechanisms. This information is necessary to better understand the removal mechanism of R. sphaeroides, and is significant for its pilot test and future practical application.

Removal of Uranium From Aqueous Solution by Chitosan and Ferrous Ions

2010 ◽  
Author(s):  
Jing-song Wang ◽  
Zheng-lei Bao ◽  
Si-guang Chen ◽  
Jin-hui Yang
Keyword(s):  
Aqueous Solution ◽  
Removal Rate ◽  
Synergetic Effect ◽  
Ferrous Ions ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Batch Systems ◽  
Uranium Ions ◽  
High Removal Rate ◽  
The Given

This study focuses on developing a new method to remove uranium from aqueous solution. Chitosan and ferrous ions were used together to remove uranium ions from aqueous solution. Through two-step pH adjustment, the uptake behavior of chitosan and ferrous ions toward uranium in aqueous solution using batch systems were studied in different experimental conditions. The experimental results indicated that the removal of uranium by synergetic effect of chitosan and ferrous ions was more effective than the way of adsorbing uranium ions by chitosan alone. Under the given experimental conditions, the concentration of the residual uranium in the effluent after chitosan and ferrous ions treatment could meet the discharge standard (< 0.05mg·l−1) when initial concentration of uranium ions was 10 mg·l−1 or 100 mg·l−1. The synergetic effect of chitosan and ferrous ions including adsorption, coacervation and coprecipitation, are responsible for the high removal rate of uranium.

Pretreatment of furfural industrial wastewater by Fenton, electro-Fenton and Fe(II)-activated peroxydisulfate processes: a comparative study

2014 ◽  
Vol 70 (3) ◽  
pp. 414-421 ◽  
Author(s):  
C. W. Yang ◽  
D. Wang ◽  
Q. Tang
Keyword(s):  
Comparative Study ◽  
Industrial Wastewater ◽  
Ph Value ◽  
Removal Rate ◽  
Aeration Rate ◽  
Cod Removal ◽  
Optimal Conditions ◽  
Initial Concentration ◽  
Cod Removal Rate ◽  
Pretreatment Technology

The Fenton, electro-Fenton and Fe(II)-activated peroxydisulfate (PDS) processes have been applied for the treatment of actual furfural industrial wastewater in this paper. Through the comparative study of the three processes, a suitable pretreatment technology for actual furfural wastewater treatment was obtained, and the mechanism and dynamics process of this technology is discussed. The experimental results show that Fenton technology has a good and stable effect without adjusting pH of furfural wastewater. At optimal conditions, which were 40 mmol/L H2O2 initial concentration and 10 mmol/L Fe2+ initial concentration, the chemical oxygen demand (COD) removal rate can reach 81.2% after 90 min reaction at 80 °C temperature. The PDS process also has a good performance. The COD removal rate could attain 80.3% when Na2S2O8 initial concentration was 4.2 mmol/L, Fe2+ initial concentration was 0.1 mol/L, the temperature remained at 70 °C, and pH value remained at 2.0. The electro-Fenton process was not competent to deal with the high-temperature furfural industrial wastewater and only 10.2% COD was degraded at 80 °C temperature in the optimal conditions (2.25 mA/cm2 current density, 4 mg/L Na2SO4, 0.3 m3/h aeration rate). For the Fenton, electro-Fenton and PDS processes in pretreatment of furfural wastewater, their kinetic processes follow the pseudo first order kinetics law. The pretreatment pathways of furfural wastewater degradation are also investigated in this study. The results show that furfural and furan formic acid in furfural wastewater were preferentially degraded by Fenton technology. Furfural can be degraded into low-toxicity or nontoxic compounds by Fenton pretreatment technology, which could make furfural wastewater harmless and even reusable.

Study on the Adsorption Effect of ZnCl2-Modified Pomelo Peel Powder on Wastewater Containing Pb (II)

2013 ◽  
Vol 726-731 ◽  
pp. 2320-2323 ◽  
Author(s):  
Qing Shan Pan ◽  
Wei Liu ◽  
Mei Gui Mao ◽  
He Ping Yan ◽  
Du Shu Huang ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Removal Rate ◽  
Adsorption Effect ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Pomelo Peel ◽  
Effects Of Ph

The modified pomelo peel powder was prepared by using chemical modification methods of ZnCl2soaking and heating.The removal rate of Pb (II) ion in simulation of wastewater by the modified pomelo peel powder was tested. The effects of pH of wastewater, initial concentrations of Pb (II) ion, adsorbent dosage,temperature and time on adsorption of Pb (II) ion was studied. Results show that when Pb (II) ion initial concentration at 100 mgL-1, pH of wastewater at 3.5-5.5, adsorption time at 100min, adsorbent dosage at 15gL-1, temperature at 35°C, the removal rate of Pb (II) ion in simulation of wastewater by the modified pomelo peel powder was more than 95%.

Study on Cu2+ Removal from Water via an Cation Exchange Membrane

2012 ◽  
Vol 253-255 ◽  
pp. 954-959
Author(s):  
De Hua Xie
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Potassium Ions ◽  
Inlet Concentration ◽  
Experimental Conditions ◽  
External Voltage ◽  
Initial Concentration ◽  
Exchange Membrane

The removal of Cu2+ in water via an ion-exchange membrane under no external voltage condition was studied in the research, and effects such as Cu2+ concentration, concentration of compensation potassium ions, water stirring speed, temperature and hydraulic retention time (HRT) on the removal efficiency of Cu2+ were also investigated. The results showed that when the initial concentration of bivalent ion Cu2+ was 0.0787mmol/L （5mg/L）, under the experimental conditions of the water temperature at 25 °C , the HRT was 6h, the hydraulic mixing speed was 600±25rpm, and the concentration of the compensation ion K+ was 10 times as that of Cu2+, and the removal efficiency of Cu2+ could be achieved 85%. In addition, using the same equipments, when the inlet concentration of Cu2+ increased to 0.787mmol/L (50mg/L), the removal efficiency would be decreased to 76%; while the ratio of concentration of compensation potassium ions to that of inlet Cu2+ is larger than 20, the removal efficiency would not change significantly as the ratio continued increasing; the removal efficiency would be decreased to 60% when lowering the stirring speed to 300±25rpm; the removal efficiency would be decreased to 68% when lowering the temperature to 15+1 °C; the removal rate was no significant change when the hydraulic retention time (HRT) from 6h to 12h.

Disposal of 3.5-dinitro-benzoicacid Wastewater by Semi-Coke/Ozone Combined Technology

2014 ◽  
Vol 997 ◽  
pp. 732-735
Author(s):  
Nan Nan Dang ◽  
Hui Wu Cai ◽  
Jin Meng Zhu
Keyword(s):  
Reaction Time ◽  
Benzoic Acid ◽  
Removal Rate ◽  
Catalytic Ozonation ◽  
Flow Temperature ◽  
Initial Concentration ◽  
Maximum Value ◽  
Effects Of Ph ◽  
Cod Removal Rate ◽  
Better Than

The effects of pH, initial concentration, ozone flow, temperature and semi-coke dosage on 3.5-dinitro-benzoic acid wastewater in the process of carbocoal catalytic ozonation are investigated. The results show that: the removal rate of COD increases with the rise of ozone flow and reaction time in a certain range; temperature has little effect on the removal rate of COD; the removal rate of COD achieve the maximum value when the pH is about 12; the COD removal rate of carbocoal catalytic ozonation is obviously better than single ozonation.

scholarly journals Optimization of Deep Oxidative Desulfurization Process Using Ionic Liquid and Potassium Monopersulfate

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Yinke Zhang ◽  
Hang Xu ◽  
Mengfan Jia ◽  
Zhuang Liu ◽  
Deqiang Qu
Keyword(s):  
Response Surface Methodology ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Time ◽  
Removal Rate ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Desulfurization Process

Response surface methodology (RSM) was selected to optimize a desulfurization process with metal based ionic liquids ([Bmim]Cl/CoCl2) and potassium monopersulfate (PMS) together to remove benzothiophene (BT) from octane (simulating oil). The four experimental conditions of PMS dosage, [Bmim]Cl/CoCl2 dosage, temperature, and reaction time were investigated. The results showed that the quadratic relationship was built up between BT removal and four experimental variables with 0.9898 fitting coefficient. The optimal conditions were 1.6 g (20 wt%) PMS solution, 3.2 g [Bmim]Cl/CoCl2, 46°C, and 23 min, which were obtained based on RSM and experimental results. Under the optimal condition, predicted sulfur removal rate and experimental sulfur removal rate were 96.7% and 95.4%, respectively. The sequence of four experimental conditions on desulfurization followed the order temperature > time > [Bmim]Cl/CoCl2 dosage > PMS solution dosage.

Oxidative Degradation of Azo Dye Reactive Red 2BF by Potassium Ferrate

2012 ◽  
Vol 518-523 ◽  
pp. 2617-2620 ◽  
Author(s):  
Xiao Li Dong ◽  
Lei Wang ◽  
Xin Xin Zhang ◽  
Lin Bai ◽  
Xiu Fang Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Azo Dye ◽  
Removal Rate ◽  
Oxidative Degradation ◽  
Potassium Ferrate ◽  
Optimal Conditions ◽  
Initial Concentration ◽  
Cod Removal Rate ◽  
Degradation Of Azo Dye

The oxidative degradation of azo dye Reactive Red 2BF in aqueous solution by using potassium ferrate (Ⅵ) was studied. The initial concentration of wastewater 100 mg/L, pH 4.0, reaction time 20 min, and the dosage of potassium ferrate was 0.9 g/L. Under the optimal conditions, the decolorizing rate of Reactive Red 2BF and the COD removal rate were 99.9% and 73.3%.

A Simple Method for Estimation of Lipoxygenase and Cyclo-Oxygenase Pathways in Human Platelets - the Use of Thiobarbituric Acid Reaction

1980 ◽  
Vol 44 (02) ◽  
pp. 111-114 ◽  
Author(s):  
Hiroshi Takayama ◽  
Minoru Okuma ◽  
Haruto Uchino
Keyword(s):  
Time Course ◽  
Normal Values ◽  
Human Platelet ◽  
Thiobarbituric Acid ◽  
Human Platelets ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Simple Method ◽  
Acid Reaction ◽  
Optimal Ph

SummaryTo develop a simple method for estimation of platelet lipoxygenase (PLO) and cyclo-oxygenase (PCO) pathways, the arachidonic acid (AA) metabolism of human platelet was investigated under various experimental conditions by the use of the thiobarbituric acid (TBA) reaction and a radioisotope technique. A TBA-reactive substance different from malondialdehyde (MDA) via PCO pathway was detected and shown to be derived from the PLO pathway. Since the optimal pH and time course of its formation were different from those of MDA formation via PCO pathway, PLO and PCO pathways were estimated by quantitating the TBA-reactive substances produced by the incubation of AA either with aspirin-treated platelets or with untreated ones, respectively, each under optimal conditions. Normal values expressed in terms of nmol MDA/108 platelets were 1.17±0.34 (M±SD, n = 31) and 0.79±0.15 (n = 31) for PLO and PCO pathways, respectively.

In vivo Production of Soluble Inorganic Pyrophosphatases in Two Strains of Vibrio cholerae

1970 ◽  
Vol 24 (1) ◽  
pp. 38-41
Author(s):  
Taslima Taher Lina ◽  
Mohammad Ilias
Keyword(s):  
Vibrio Cholerae ◽  
Specific Activity ◽  
Experimental Conditions ◽  
Environmental Strain ◽  
Cell Extracts ◽  
Atcc Strain ◽  
The Family ◽  
Effects Of Ph ◽  
Vibrio Cholerae O1

The in vivo production of soluble inorganic pyrophosphatases (PPases) was investigated in two strains, namely, Vibrio cholerae EM 004 (environmental strain) and Vibrio cholerae O1 757 (ATCC strain). V. cholerae is known to contain both family I and family II PPase coding sequences. The production of family I and family II PPases were determined by measuring the enzyme activity in cell extracts. The effects of pH, temperature, salinity of the growth medium on the production of soluble PPases were studied. In case of family I PPase, V. cholerae EM 004 gave the highest specific activity at pH 9.0, with 2% NaCl + 0.011% NaF and at 37°C. The strain V. cholerae O1 757 gave the highest specific activity at pH 9.0, with media containing 0% NaCl and at 37°C. On the other hand, under all the conditions family II PPase did not give any significant specific activity, suggesting that the family II PPase was not produced in vivo in either strains of V. cholerae under different experimental conditions. Keywords: Vibrio cholerae, Pyrophosphatases (PPases), Specific activityDOI: http://dx.doi.org/10.3329/bjm.v24i1.1235 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 38-41

scholarly journals Degradation of hydroxypropyl guar gum at wide pH range by a heterogeneous Fenton-like process using bentonite-supported Cu(0)

2020 ◽  
Vol 82 (8) ◽  
pp. 1635-1642
Author(s):  
Ling Zhou ◽  
Zhongying Xu ◽  
Jie Zhang ◽  
Zhifang Zhang ◽  
Ying Tang
Keyword(s):  
Active Sites ◽  
Guar Gum ◽  
Heterogeneous Reaction ◽  
Removal Rate ◽  
Catalytic Performance ◽  
High Dispersion ◽  
Application Process ◽  
Experimental Conditions ◽  
Hydroxypropyl Guar ◽  
Hydroxypropyl Guar Gum

Abstract To seek for efficient Fenton-like oxidation processing for treatment of waste fracturing fluid containing hydroxypropyl guar gum (HPGG), in heterogeneous reaction, five bentonite-supported zero-valent metal catalysts were prepared by liquid-phase reduction. The results showed that the bentonite-supported zero-valent copper exhibited best catalytic performance, attributed to the high dispersion of active sites of zero-valent copper. The effects of the most relevant operating factors (H2O2 concentration, catalyst dosage, temperature and pH) were evaluated in detail. Moreover, the chemical oxygen demand removal rate of HPGG can achieve 76% when the reaction time was selected at 45 min under optimal experimental conditions. The stability evaluation showed that the catalytic performance was almost unaffected after the catalyst was recycled and used once more showing the good stability of the bentonite-supported zero-valent copper in the application process.

Sign in / Sign up

Export Citation Format

Share Document